allowsSelectionDuringEditing property for NSTableView - nstableview

Question

Application I'm trying to develop is heavily built around being able to have editable TableViews. I'm beginning to conclude that most if not all of my problems stem from the fact that I do not see allowsSelectionDuringEditing available for NSTableView as it is for UITableView.
First, would like to get insight into why.
Second, how do I go about implementing one in my NSTableView class?
Finally, I have a NSSegmentedControl in one of my columns. So I need to implement allowSelectiongWhenFocused property somewhere, because while I have focus on the button and allowing user to use <- and -> with spacebar to select switch(es), I don't want mouse / keyboard from changing the selected row.
As an aside, while I now know how to write custom UI classes and hook them into Interface Builder, I'm struggling on when/whether to customize NSTableView, NSTableRowView, NSTableCellView or NSSegmentedControl. I've tried to understand how refuseFirstResponder works as well. Trial and error is not getting me anywhere - I fix something and break something somwehre else. If someone can suggest any other reading besides Apple documentation (sometimes I suspect if it is in English) would really appreciate it.

Answer 1

Here's what I would do:
Subclass NSTableRowView and override hitTest(_:). If the row is not selected then the row view returns itself instead of a control. The first click in a row selects the row and doesn't change the value of a control.
override func hitTest(_ point: NSPoint) -> NSView? {
let view = super.hitTest(point)
if view == nil || self.isSelected {
return view
}
else {
return self
}
}
Implement NSTableViewDelegate's tableView(_:rowViewForRow:) to use the custom row view:
func tableView(_ tableView: NSTableView, rowViewForRow row: Int) -> NSTableRowView? {
return MyTableRowView()
}
Implement NSTableViewDelegate's selectionShouldChange(in:) so a row can't be deselected if the values aren't valid or other conditions aren't met.
func selectionShouldChange(in tableView: NSTableView) -> Bool {
let row = tableView.selectedRow
if (row >= 0) {
return self.validateRow(row)
}
else {
return true
}
}